This application proposes a pilot study to develop and test a new procedure for the detection and quantitation of contractile activity in the periodontal membrane of laboratory animals. Previous work by one of the applicants and by other investigators suggests that the contractile fibroblast (myofibroblast) may play a fundametal role in the eruptive, drifting, and orthodontic movements of teeth. By means of a pair of thin platinum electrodes inserted into the periodontal tissue, it is proposed to deliver either a direct or a pulsed voltage of defined amplitude, frequency, and duration. The tooth would then be monitored for any movement or oscillation resultant from the electrical pulsing, by either one or a combination of the following methods: optical (laser holography; miniature light emitting diode: matched detector coupling) or electromechanical (pressure transducers; mechanical Piezo crystal detectors; and variable capacitance). The method selected must be able to resolve myofibroblastic contraction in the presence of other muscular contraction. The rationale of this study is centered upon the fact that the myofibroblast has the intracellular apparatus to contract and the anatomical linkage with collagen to exert a pull on the tooth. Since smooth and striated muscular tissue exhibit a contractile response to electrical stimuli, it is felt that the myofibroblast will also behave in this fashion. The initial phase of this study will utilize induced biological preparations having a dense myofibroblast population and a scant presence of other contractile elements (e.g., Selye's Granuloma Pouch, avascular blood clot capsule). These preparations will be studied in order to develop a specific pattern of excitation and a discriminative analysis of the resultant contraction which will permit an exclusive focus on the myofibroblastic response in the periodontal membrane. An attempt will also be made to uncover any specific electrical fields that emanate from the myofibroblastic network during contraction, which might prove useful in identifying and monitoring myofibroblastic activity in normal and pathological conditions (much as the EKG is used to monitor heart muscle status).